Walking emissions estimate
This is a directional avoided-emissions estimate, not a measured reduction, carbon offset, credit, or contribution to a corporate greenhouse-gas inventory.
- Evidence label
- Estimated
- Method ID
- walking-vs-average-petrol-car
- Version
- 2026.1
- Factor
- 0.150 kg CO₂e per kilometre
- Activity data
- Walking distance recorded for a completed quest
- Counterfactual
- The same distance travelled in an average petrol car
Formula
Estimated kg CO₂e avoided = completed quest walking distance in kilometres × 0.150 kg CO₂e/km.
The value is recorded once per completed quest progress record. Replaying or ending navigation does not create additional credit.
What must be true
The estimate assumes the recorded walk replaced a trip of the same distance in an average petrol car. When that substitution did not occur—for example, the person would otherwise have walked or not travelled—the real avoided emissions are zero.
Boundary and exclusions
The method does not adjust for vehicle occupancy, model, traffic, route detours, driving style, public transport, electric vehicles, device error, infrastructure, embodied emissions, or lifecycle emissions. It does not subtract food-energy or device use associated with walking. Results should not be aggregated with measured greenhouse-gas inventory reductions.
Sources and governance
The product factor is a conservative rounded baseline informed by the UK Government's current greenhouse-gas conversion factors. Reporting treatment follows the GHG Protocol guidance that avoided emissions be disclosed separately with a clear baseline, boundary, data source, and assumptions.
- UK Government greenhouse-gas reporting conversion factors 2025
- GHG Protocol: Estimating and Reporting Avoided Emissions
Method versions are retained on each estimate. The factor and boundary are reviewed when an authoritative source changes and at least annually; changes create a new version rather than silently rewriting historical records.